Investigational Tracer Iodine-124 Evuzamitide PET Shows 94% Sensitivity for Cardiac Amyloidosis in Single-Arm REVEAL Trial

On August 30, 2026, investigators led by Dr. Sharmila Dorbala, principal investigator of the Phase III REVEAL trial and Director of Nuclear Cardiology at Brigham and Women’s Hospital, reported that positron emission tomography (PET) with iodine-124 evuzamitide identified cardiac amyloidosis with 94% sensitivity and 86% specificity in 170 analyzed patients. The results, presented as a late-breaking oral presentation at ESC Congress 2026 in Munich and published in JAMA the same day, put peer-reviewed accuracy figures behind an investigational tracer that Bayer is developing for more than one amyloid type.

The tracer, also known as AT-01, isn’t approved anywhere. REVEAL is an investigator-initiated study sponsored by Brigham and Women’s Hospital. Dorbala is also Director of Amyloidosis Research at Mass General Brigham Heart & Vascular Institute. Bayer, which says it acquired the tracer from Attralus, issued its own release on the REVEAL results through Business Wire.

The stakes come down to which patients current imaging can serve. The JAMA authors wrote that existing imaging approaches are limited to transthyretin amyloidosis (ATTR). REVEAL tested the tracer in adults whose amyloidosis diagnosis wasn’t yet established, and Bayer reported separate results for ATTR and for light-chain amyloidosis (AL) as secondary endpoints. Bayer says the U.S. Food and Drug Administration (FDA) granted the tracer Breakthrough Therapy Designation for PET imaging in suspected or known cardiac amyloidosis, and that it holds Orphan Drug status for AL and ATTR in the U.S. and EU.

How REVEAL tested iodine-124 evuzamitide PET

According to the JAMA paper, REVEAL enrolled 195 adults at 18 U.S. centers and analyzed 170. The study ran from January 14, 2025, through March 12, 2026, including 60-day follow-up. Patients who already carried an amyloidosis diagnosis were excluded. That makes this a test of the tracer in patients who need a diagnosis, not a demonstration in the already-known.

Three physicians experienced in cardiac PET/computed tomography (PET/CT) read each scan independently, blinded to clinical data. A separate panel of three amyloidosis experts, blinded to the PET results, adjudicated the final diagnosis. Against that reference standard, sensitivity was 94% (95% confidence interval [CI], 85% to 98%), specificity was 86% (77% to 92%), positive predictive value was 85%, and negative predictive value was 94%.

The protocol is a single 1 mCi intravenous injection with imaging 3 to 5 hours later. Patients also took 130 mg of potassium iodide by mouth for 3 days, starting at least 30 minutes before injection, so each exam in the trial came with a three-day medication course.

Reader and subtype results reported by Bayer

According to Bayer, sensitivity was 94% (85% to 98%) for Reader 1, 94% (85% to 98%) for Reader 2, and 90% (81% to 95%) for Reader 3, with specificity of 84% (75% to 91%), 85% (76% to 92%), and 89% (81% to 95%). The majority read, defined as at least two of three readers agreeing, produced the same 94% sensitivity and 86% specificity reported in JAMA.

Each of those numbers measures one reader’s agreement with the adjudicated diagnosis. None measures how often the readers agreed with each other.

Bayer lists the subtype results as secondary endpoints on the majority read. It reports ATTR sensitivity of 96% (87% to 100%) with specificity of 86%, and AL sensitivity of 95% (76% to 100%) with specificity of 86%. Neither Bayer’s release nor the JAMA abstract supplies subtype definitions or denominators.

Bayer calls the tracer “pan-amyloid,” a term from the title of its own acquisition announcement. It isn’t a regulatory category, and an AL sensitivity estimate with a lower bound of 76% is an early signal, not a settled claim about every amyloid type.

Safety data from the REVEAL trial

Bayer reports that 55 of 170 patients (32.4%) had at least one treatment-emergent adverse event between Day 1 and Day 30. Eleven patients (6.5%) had serious events, all judged unrelated to the tracer. One event, fatigue, was judged tracer-related. There were no deaths, and no tracer-related event led to discontinuation. Without a comparator arm, these figures can’t show how the event rate compares with what the same patients would have experienced otherwise.

What REVEAL didn’t measure

The strongest case for caution is built into the design. REVEAL is a single-arm, nonrandomized diagnostic accuracy study. It measured iodine-124 evuzamitide PET against expert adjudication, not against technetium-99m pyrophosphate (Tc-99m PYP) imaging or fluorine-18 amyloid tracers. Diagnostic accuracy also doesn’t establish that patients do better because they were scanned.

The positive predictive value deserves a plain reading. At 85%, roughly 15 of every 100 positive reads in this population were patients the adjudication panel judged not to have amyloidosis. How that translates to a referral population with a different prevalence is an open question.

The reported diagnostic-accuracy results also don’t establish commercial availability or reimbursement for the tracer.

Bayer’s stated plans with the FDA

The May 7, 2026, Bayer topline announcement on REVEAL said both primary endpoints were met but gave no figures. That release cited 19 centers, one more than the 18 reported by JAMA and Bayer’s August release.

In its May 7 and August 30 releases, Bayer said it planned to discuss the data, and a regulatory submission, with the FDA and other health authorities. Those announcements did not report a filing or specify a submission date. Whether reliable AL detection and an advantage over ATTR-limited imaging hold up will depend on subtype denominators and comparative data that the published results don’t yet supply.

About the sources: The overall accuracy figures, study design, and dosing come from the abstract and key points of the JAMA paper, “124I-Evuzamitide Positron Emission Tomography/Computed Tomography for Diagnosing Cardiac Amyloidosis: The REVEAL Nonrandomized Clinical Trial”; the full text was not available. The reader-level, subtype, and safety figures come from Bayer’s August 30, 2026, release, distributed through Business Wire and republished by BioSpace, and are Bayer’s reporting. The JAMA author list includes a Bayer AG employee, Spencer Guthrie, and Bayer’s release draws on the same dataset, so the two accounts are not independent of each other.